In addition, the invention relates, in particular, to a method for determining the average temperature of the steam issuing from a steam generator, wherein a fuel is burned with an oxidizer in a combustion chamber of the steam generator and in addition water is injected into the combustion chamber.
The methods previously known for determining the quickly changing, average temperature of a flow of compressible medium always provide for direct measurement of the temperature itself, and the conventional temperature sensors, such as, for example, thermometers, are utilized.
The conventional temperature sensors have the disadvantage that they have relatively long response times and therefore sudden changes in temperature can be recreated only with delay so that problems always occur when temperature measurements of this type are to be taken into account in control processes.
The object underlying the invention is therefore to improve a method of the generic type such that it is possible to ascertain sudden changes in temperature accurately and with the least possible delay in time.
This object is accomplished in a method for determining the quickly changing, average temperature of a flow of compressible medium in that the medium is caused to flow through a throttle point, that the mass flow of the medium flowing through the throttle point is determined, that the pressure inside and upstream outside the throttle point is ascertained and that the average temperature is determined on the basis of the mass flow and the pressure, in particular the difference in the pressure inside and upstream outside the throttle point. This average temperature can be mathematically calculated from the values used for determination.